In general, heat exchangers are devices that transfer thermal energy between two fluids without direct contact between the two fluids. A primary fluid is typically directed through a fluid core of the heat exchanger while a secondary cooling or heating fluid is brought into external contact with the fluid core. In this manner, thermal energy may be transferred between the primary and secondary fluids through the walls of the fluid core.
The ability of the heat exchanger to transfer thermal energy between the primary and secondary fluids depends on, amongst other things, the surface available for the heat transfer and the thermal properties of the exchanger materials.
A vast number of various types of heat exchangers exist in the field. One of these is disclosed in U.S. 20090084520. This publication shows a heat exchanger comprising a plurality of hexagonal elongate elements, each of the elements having a central channel for a flow of a first fluid. Around the central channel, the elements comprises a metal foam, which can be of an open cell structure or a combination of an open cell structure and a closed cell structure. A second fluid flows through the metal foam.
A major disadvantage of this heat exchanger is that the metal foam provides a very high flow resistance to the flow of the second fluid.
Another known heat exchanger is GB 637235. This publication shows heat exchanger with heat exchanger elements that transfers heat between two fluids. The heat exchanger elements having ribs that extends radially outwardly from the core. Every second fin is divided into two ribs. The heat exchangers are put together so that the fins produce a honeycomb formation where a fluid can flow. The shape of the ribs and fins do not transfer the heat efficiently between the two fluids. The heat exchanger are equal and only shaped to fit a juxtaposed heat exchanger element. The shape is not fitted to the outer casing surrounding the heat exchanger element. There are some empty space between the casing and ribs/fins of the heat exchanger element which results in uneven heating or cooling of the fluid. The honeycomb formation are also less efficient to transfer heat since there are a large space between the fins and ribs.
The publication CN201229141 shows a heat exchanger elements with ribs that divides into two radially extending fins, but the ribs and fins in this publication are not extending continuously in parallel with the core along the whole length of the core, instead they are helically arranged around the core. This will reduce the flow of the fluid through the heat exchanger element and require more energy to transport the fluid through the heat exchanger. The ribs are also arranged with some space between the ribs which also do not increase the efficiency of the heating or cooling.
None of the publications disclose a heat exchanger element where the inlet port and outlet port are arranged at the same end of the core, which provides a better heat transmission between the fluids.
Other known heat exchangers are shown in DE2742877, BE673093, IT7848277, U.S. Pat. Nos. 3,595,310, 2,729,433, US20090107853, EP305702, AU7943132, GB1413913, US20140000845 and WO201091178. However, common to these is that the flow of one of the fluids is restricted by elements of the heat exchanger. These restrictions increase the need of energy (pressure) to ensure a sufficient flow of the fluid.
Heat sinks are used in electronic system to cool for instance central processing units or graphic processors by dissipating heat into the surrounding medium. Heat sinks having fins that extend from its base and increase the area of heat transfer. The base and fins are in direct contact with the heat source for cooling of the electrical unit.
The heat exchanger according to the invention are not equivalent and not suitable for use in heat sinks for cooling central processing unit or similar electrical units. The heat sinks are much smaller to fit in the electronic device than the heat exchanger according to the invention. In the heat exchanger according to the invention, the heat is transferred from a fluid to another fluid to be used as a heating or cooling of a surrounding gas or a liquid.